Methods of producing fumaric acid



Patented Jan. 10, 1950 David Levin, Philadelphia,

cal Concentrates Corpora ton, Pa., a corporationpl No Drawing. Appli Serial No.

14 Claims. (Cl. zea -531) This invention relates to the production of fumaric acid and more particularly to methods of producing fumaric acid from liquors containing maleic acid.

An object oi this invention is to produce fumaric acid efficiently and economically.

Another object of this invention is to recover the values from maleic liquor in a usable form.

Another object of this invention is to obtain fumaric acid from liquors containing maleic acid which were ordinarily discarded.

In the production of phthalic anhydride, the scrub liquor contains maleic acid in addition to smaller quantities of other organic compounds. These liquors are frequently discarded because of the unavailability of a satisfactory method for the recovery of the maleic acid values from such liquor. Many methods have heretofore been proposed for this purpose, but they require elaborate equipment and are ineflicient in operation or result in small yields. Likewise, in the production of maleic acid from benzol or other raw materials, maleic liquors are formed containing many impurities.

In accordance with this invention, methods are provided whereby the maleic acid values may be recovered in good yield efliciently and economically. The method vention comprises, in one aspect, reacting in an aqueous solution maleic acid with hydrochloric or hydrobromic acid in the presence of an alkali metal chloride, an alkali metal bromide, ammonium chloride or ammonium bromide. The

amount of maleic acid employed in this process is desirably 0.1 to 10 mols and preferably 3 to 5 mols per liter of water present. The amount of hydrochloric or hydrobromic acid used is desirably 0.1 to 15 mols and preferably 1 to 4 mols per liter of water present, and the amountoi the alkali metal chloride or bromide or ammonium chloride or bromide is desirably 0.1 mols per liter of water present to the solubility of the halide. Preferably, the amount of halide is 3 to 5 mols per liter of water present. The yield of fumaric acid is related to the molar concentration of the halogen acid and/or halide salt and/or maleic acid. However, if too high a concentration of maleic acid is used, then the separated fumaric acid forms too heavy a slurry to handle satisfactorily.

The reaction in the aqueous solution of the maleic acid with the hydrochloric or hydrobromic acid in the presence of the specified halides results in the production of fumaric acid. The resulting tumaric acid may be readily sepin accordance with this in- Pa.,-assignor to Chemitiom- Fort Washing-- Pennsylvania cation July so, 1948.

arated from the mixture by any suitable means, such as filtration, decantation or centrifugation. Inaccordance with another aspect of this invention, fumaric acid is produced from alkali metal maleates or ammonium maleates. In this aspect of the invention, the method is substantially the same, namely, the alkali metal maleate or ammonium maleate is reacted in an aqueous solution with hydrochloric or hydrobromic acid in the presence of an alkali metal chloride, an alkali metal bromide, ammonium chloride or ammonium bromide. The amount of alkali metal maleate or ammoniui nmaleate used is the same molar amount as thatof the maleic acid used intheproduction of fumaric acid heretofore described. The amount of hydrochloric or hydrobromic acid is also the same as employed when maleic'acid is used as a starting material except that in addition there must be used an amount equivalent to the'theoretical amount required for the conversion of the alkali metal maleate or ammonium maleate to maleic acid. The amount of alkali metal chloride, alkalimetal bromide, ammonium chloride or ammonium bromide is also the sameas that employed when maleic acid is used as a startin material. However, the amount of alkali metal halide or ammonium halide resulting from the reaction of thealkali metal maleate or ammonium maleate 30 with the hydrochloric acid or the hydrobromic acid must be calculated as part of the alkali metal or ammonium halide present.

The process 01 this invention is admirably adapted forthe recovery of maleic acid values from scrub liquor resulting from the production 3 liquor is partially neutralized by 50 acid maleate.

of phthali'c anhydride. In this process, the scrub liquor which contains appreciable amounts of maleic acid, such as of the order of 15 to 30% by weight, is ordinarily discarded. This sitnation results not only in an economic waste but may also involve a problem of stream pollution. The maleic acid values in such scrub liquor may be recovered as fumaric acid by the methods of this invention. The maleic acid in the scrub the addition of sodium carbonate, sodium bicarbonate or sodium hydroxide until the pH of the liquor is within the range of 3.5 to 3.7. This partial neutralization converts the maleic acid to sodium The mixture is then cooled to below 25 C. and the precipitated sodium acid maleate is separated from the mixture by any suitable means, such as filtration, decantation or centrifugation. The resulting precipitated sodium acid maleate is then reacted in an aqueammonium bromide. The sodium chloride or soupon the deviation from the temperature of dium bromide formed by the reaction of the S- 110 C At higher than atmospheric pressures dium acid maleate with the iwdrochloric or hythe reaction time is shortened due to higher opdrobromie aciddscalculated as pomr oatho esating temperatures. Themeaction mixture in metal chloride alka'lig metal brsfimmfli'ilum thid exanxplae, .-rep1=.esenfis d;he; desired molar ratio chloride or ammonium bromide present. The of reactants and catalysts to achieve the most of the p ce s re he amefifififlfififitfifit used and'G'moIs of hydrochloric acid per liter of described. The resulting acidoformedi wateepnesentwas-used. The sodium acid maleate filtration, decantation or c r. About'e llechiwidezleavirig 2'm0ls of free hydrochloric acid to theoretical yields base Lupo till; maleic acid equivalent of the normed or have been obtained in two hours of processing Emmle g gfgg g from by the practice of this method. a

The presence of the small metal chloride, the 20 464 grams of maleic acid are dissolved in 840 cc. alkali metallqlbromide iwho ohtorides; on 0% waterwands234'grams otsodiumwhloride-and ammonium? brgmide fis jeawifl ifwf" 2M.cci.of.20 Baa-ima-hydrochloricacidsisadded .t maximum,yield ofi fum m mf tmthesolution Theimi-xtureisrheated-to-boilinga aneoonom tem m 11 m Med for a period of about two hours.r- Theamixtune over any; ofiotheemethodeuherehoimepmpos d 25 istheneooled to about-25 andlthe preeimtated such alkali metal harlidesmmamnimmhaiides: ric acid was drained and washedl acceleratesribstazmaialiy, thee reactions one!" Ezmpzer s pf p fiofi umafic; acid mm methods in, whieh'otheml'dmohlonimzom o'flrow sodium mmafta f bromie acid-salons iaemmoggd-cFor-wenin v tests coaductadobothnwitlimwnda-withuutssuchi so 2 grams of sodlym m me e lv m -o n, halidmpw hand m 270 cc. of water. To this solutionis added 1205 identicahconditionsdm irmtmithf'iflafivarfldl rams of s hydrotiromic acid..- The. mixtur is maletcoaeid; itowam, r :n

ifiim u ofi'wfi l 92F91 25 and the uma acid formed is f thetheoml md dfailiedofrom the mixture and .washed free .ot Denna of time acld and salt. It then vmay be .drled,.if desired Examples-obaibaumatahmmtea amsodimm The terms andflpressions hl h veemmaleate sodiu aeid meat massmmflem Dibl 'efi are used as terms of description andlnot potassiuimfl Mid; Mute nwlmnmwrmdq he of l mitation, and I have no intention, in the-use lithium aeidmaleabez ofnesucmterms and expressions, ofexeludingany Exammes ohamamzmummsdam tmm. edltiil'alents of the featurestshown and. described names are sodimnrchlomdmemdmimib a ..o.- I Dil s h f. but: recognizethat varioust m chloride. W mm lithium; modifications are possible within the scope "OfrthG? chloride ands-lithium moms minveqtiomclaimd A- more oompreheasiwe tmeim ,015 zthisv W118i is) fllfiimfid i inventiontis ohtamembyerefenenemta-thmfollow ---T method of du in fumaric acid? ing examples;v whichucomprises' reacting in: an: aqueous som m z gi malezoacidmthfid .tolfimolspen liter-oi waters tamect as o te mmatehe mdikfiwwf theclass. consisting. of hydroch zmthalzc anh drohromiaacidinuthe presence of. 0.1 mol per gals; ot a scrub liquoriobtainediasaibgo 135110! wa r-present to the Solubility limitor a.- product in thexproductiompidihtfialie anhydrldm halide selected lromtthe class consisting of alkalia and ,containingaboutl mi -gaflbriofun aleie nietal chlorides, alkali. metal bromid acid .washneut'ralizedcwith causticsodmuntii the ilm lbri c and ammoniumlbromideiand sepa,- pH f t liquor was g; 33: Aflgmflhe d rating-,the resultingiumaric acid from the mixtion or the caustic soda the tempenatm-eootatheo WT?! mixture was lowered toal iouiimiics Theprecipiaflu method of producing fumaric a id tatedsocliumacid maleateiormed'hwas drained. which D t g. in an aqueous soluand Washed. with m h amma trea s to 5 .molsiper lite of water present of 3 molecules ofwater von;cizysu ilisation, Thesoo drvbmmicaanid in the presence of 8 o 5 m sp wet crystals of sodium mm lm litezwof. water present of ahalldeselected frominoa glasslinedreaction Ketflmandta themWere: thei l ss' onsisting ofialkali metal chlorides, added 'lbsr of 20 Baumfihydroohlerieiaeids alkali: metal bromides, ammonium chloride and if crystals-aresufiiciently.wetoW'Iihereaction-mi'xa 3,-The method of producing fumaric acid ture was boiled at aboutJlO'FLC. foba period-op which comprises reacting, inarr-om nou SOlu-rtwo hours at atmospheric pressure duringowhicha time, about 4 mols of maleic acid per liter of water time the fumarie acid wasipgoducadahowentem -fllpr sent with about 2 mols per. liter of water:

present of free hydrohalogen acid selected from the class consisting of hydrochloric acid and hydrobromic acid in the presence of about 4 mols per liter of water present of a halide selected from the class consisting of alkali metal chlorides, alkali metal bromides, ammonium chloride and ammonium bromide and separating the resulting fumaric acid from the mixture.

4. The method of producing fumaric acid which comprises reacting, in an aqueous solution, 0.1 to mols per liter of water present of a member selected from the class consisting of alkali metal maleates and ammonium maleates with a hydrohalogen acid selected from the class consisting of hydrochloric acid and hydrobromic acid in the presence of a halide selected from the class consisting of alkali metal chlorides, alkali metal bromides, ammonium chloride and ammonium bromide, and separating the resulting fumaric acid from the mixture, the amount of said hydrohalogen acid being 0.1 to mols per liter of water present above that theoretically required to convert maleate to maleic acid, and the amount of said halide being 0.1 mol per liter of water present to the solubility limit of said halide.

5. The method of producing fumaric acid which comprises reacting, in an aqueous solution, 3 to 5 mols per liter of water present of a member selected from the class consisting of alkali metal maleates and ammonium maleates with a hydrohalogen acid selected from the class consisting of hydrochloric acid and hydrobromic acid in the presence of a halide selected from the class consisting of alkali metal chlorides, alkali metal bromides, ammonium chloride and ammonium bromide, and separating the resulting fumaric acid from the mixture, the amount of said hydrohalogen acid being 1 to 4 mols per liter of water present above that theoretically required to convert the maleate to maleic acid, and the amount of said halide being 3 to 5 mols per liter of water present.

6. The method of producing fumaric acid which comprises reacting, in an aqueous solution, about 4 mols per liter of water present of a member selected from the class consisting of alkali metal maleates and ammonium maleates with a hydrohalogen acid selected from the class consisting of hydrochloric acid and hydrobromic acid in the presence of about 4 mols per liter of water present of a halide selected from the class consisting of alkali metal chlorides, alkali metal bromides, ammonium chloride and ammonium bromide, and separating the resulting fumaric acid from the mixture, the amount of said hydrohalogen acid being about 2 mols per liter of water present above that theoretically required to convert the maleate to maleic acid.

7. The method of producing fumaric acid which comprises reacting, in an aqueous solution, 0.1 to 10 mols per liter of Water present of maleic acid with 0.1 to 15 mols per liter of water present of free hydrochloric acid in the presence of 0.1 mols per liter of water present to the solubility limit of sodium chloride, and separating the resulting fumaric acid from the mixture.

8. The method of producing fumaric acid which comprises reacting, in an aqueous solution, 3 to 5 mols per liter of water present of maleic acid with 1 to 5 mols per liter of water present of free hydrochloric acid in the presence of 3 to 5 mols of sodium chloride per liter of water pres ent, and separating the resulting fumaric acid from the mixture.

9. The method of producing fumaric acid which comprises reacting, in an aqueous solution, about 4 mols perliter of, water present of maleic acid with about 2 mols per liter of water present of free hydrochloric acid in the presence of about 4 mols per liter of water present of sodium chloride, and separating the resulting fumaric acid from the mixture.

10. The method of producing fumaric acid which comprises reacting, in an aqueous solution, 0.1 to 10 mols per liter of water present of sodium acid maleate with hydrochloric acid in the presence of sodium chloride and separating the resulting fumaric acid from the mixture, the amount of hydrochloric acid being 0.1 to 15 mols per liter of water present above that theoretically required to convert the maleate to maleic acid and the amount of sodium chloride being 0.1 mols per liter of water present to the solubility limit of sodium chloride.

11. The method of producing fumaric acid which comprises reacting, in an aqueous solution, 3 to 5 mols per liter of water present of sodium acid maleate with hydrochloric acid in the presence of sodium chloride and separating the resulting fumaric acid from the mixture, the amount of hydrochloric acid being 1 to 4 mols per liter of water present above that theoretically required to convert the maleate to maleic acid, and the amount of sodium chloride being 3 to 5 mols per liter of water present.

12. The method of producing fumaric acid which comprises reacting, in an aqueous solution, about 4 mols of sodium acid maleate per liter of water present with hydrochloric acid in the presence of 4 mols per liter of water present of sodium chloride, and separating the resulting fumaric acid from the mixture, the amount of hydrochloric acid being about 2 mols per liter of water present above that theoretically required to convert the maleate to maleic acid.

13. The method of producing fumaric acid from a liquor containing maleic acid which comprises partially neutralizing the waste liquor by the addition of a member selected from the class consisting of sodium carbonate, sodium bicarbonate and sodium hydroxide until the pH of said liquor is within the range of 3.5 to 3.7, cooling the mixture to below 25 C., separating the precipitated sodium acid maleate from the mixture, reacting in an aqueous solution 3 to 5 mols per liter of water present of the separated sodium acid maleate with hydrochloric acid in the presence of sodium chloride, and separating the resulting fumaric acid from the mixture, the amount of hydrochloric acid present being 1 to 4 mols per liter of water present above that theoretically required to convert the maleate to maleic acid, and the amount of sodium chloride being 3 to 5 mols per liter of water present.

14. The method of producing fumaric acid from a liquor containing maleic acid which comprises partially neutralizing the waste liquor by the addition of a member selected from the class consisting of sodium carbonate, sodium bicarbonate and sodium hydroxide until the pH of said liquor is within the range of 3.5 to 3.7, cooling the mixture to below 25 C., separating the precipitated sodium acid maleate from the mixture, reacting in an aqueous medium about 4 mols per liter of water present of the separated sodium acid maleate with hydrochloric acid in the presence of about 4 mols of sodium chloride per liter of water present and separating the resulting fumaric acid from the mixture, the amount of hydrochloric acid being about 2 mols per liter of 9 8 at theom mquimu "Name tawomm the w w m maleic'aifl. 2395x352 -winstrom. qa,n.22, 1946 May 11, was amass 261E811! 5 OTHER REFERENCES 'me'ronowmg-referencesrew record in the gj gg figgj Deut- Chem" me of this patent: Terry etnL. J. m. Chem. 500.. vol. 47, pp.

hum]: slams mums 1412 1412: (1925) umber Name Date a wlfiimzaiki et a1.,,J.,Am.-Ghem. Sect, Vol.63, pp. 252035 1 9 Spencefittl. amy rs; 1940 

1. THE METHOD OF PRODUCING FUMARIC ACID WHICH COMPRISES REACTING, IN AN AQUEOUS SOLUTION, 0.1 TO 10 MOLS PER LITER OF WATER PRESENT OF MALEIC ACID WITH 0.1 TO 15 MOLS PER LITER OF WATER PRESENT OF FREE HYDROHALOGEN ACID SELECTED FROM THE CLASS CONSISTING OF HYDROCHLORIC ACID AND HYDROBROMIC ACID IN THE PRESENCE OF 0.1 MOL PER LITER OF WATER PRESENT TO THE SOLUBILITY LIMIT OF A HALIDE SELECTED FROM THE CLASS CONSISTING OF ALKALI METAL CHLORIDES, ALKALI METAL BROMIDES, AMMONIUM CHLORIDE AND AMMONIUM BROMIDE AND SEPARATING THE RESULTING FUMARIC ACID FROM THE MIXTURE.
 14. THE METHOD OF PRODUCING FUMARIC ACID FROM A LIQUOR CONTANING MALEIC ACID WHICH COMPRISES PARTIALLY NEUTRALIZING THE WASTE LIQUOR BY THE ADDITION OF A MEMBER SELECTED FROM THE CLASS CONSISTING OF SODIUM CARBONATE, SODIUM BICARBONATE AND SODIUM HYDROXIDE UNTIL THE PH OF SAID LIQUOR IS WITHIN THE RANGE OF 3.5 TO 3.7, COOLING THE MIXTURE TO BELOW 25*C., SEPARATING THE PRECIPITATED SODIUM ACID MALEATE FROM THE MIXTURE, REACTING IN AN AQUEOUS MEDIUM ABOUT 4 MOLS PER LITER OF WATER PRESENT OF THE SEPARATED SODIUM ACID MALEATE WITH HYDROCHLORIC ACID IN THE PRESENCE OF ABOUT 4 MOLS OF SODIUM CHLORIDE PER LITER OF WATER PRESENT AND SEPARATING THE RESULTING FUMARIC ACID FROM THE MIXTURE, THE AMOUNT OF HYDROCHLORIC ACID BEING ABOUT 2 MOLS PER LITER OF WATER PRESENT ABOVE THAT THEORETICALLY REQUIRED TO CONVERT THE MALEATE TO MALEIC ACID. 